Frequency of symptoms of attention deficit and hyperactivity disorder in autistic children.

BACKGROUND Both DSM-IV and the ICD-10 exclude diagnosis of attention deficit/hyperactivity disorder (ADHD) when autism diagnostic is present. Some authors suggest, however, that autism can be associated to other comorbidity amongst which the ADHD. OBJECTIVE To estimate prevalence of ADHD in children with autism. METHOD Children were selected from a specialized school, all of then had previous diagnosis or diagnostic suspicion of autism. The Brazilian version of the KIDDIE-SADS PL was applied to parents for diagnostic of ADHD. DSM-IV diagnostic of autism was based on parents' interview and child observation. RESULTS 32 children were included in the study. Results show that 53.1% of the ASD child had ADHD symptoms enough to fulfill DSM-IV diagnostic criteria, whereas 56.9% did not fulfill DSM-IV criteria for ADHD. CONCLUSION Results suggest a high frequency of ADHD symptoms in ASD patients. Elucidating if we are facing a comorbity or an autism distinct phenotype can contribute for a more adjusted pharmacotherapy approach for these children.